Manufacture of printing-plates



E. E. NOVOTNY.

MANUFACTURE OF PRINTING PLATES. APPLICATION FILED MAY 22. 19W. RENEWED OCT. 16. I918.

1,33 9, 127. t tfifl May 4, 1920.

51m wank- 1 UNITED STATES PATENT OFFICE.

EMIL E. NOVOTNY, OF RIVERSIDE, ILLINOIS, ASSIGNOR TO J. STOGDELL STOKES, 0F

MOQRESTOWN, NEW JERSEY.

MANUFACTURE OF PRINTING-PLATES.

Specification of Letters Patent.

Patented May 4, 1920.

Application filed May 22, 1917, Serial No. 170,161. Renewed October 16, 1918. Serial No. 258,485.

To all whom it may concern:

Be it known that I, EMIL E. NOVOTNY, a citizen of the United States, residing at Riverside, in the county of Cook and State of Illinois, have invented new and useful Improvements in the Manufacture of Printing-Plates, of which the following is a specification.

This invention relates to printing plates and method of manufacturing the same.

In the present instance it is my purpose to make a printing plate by such a method that it will have embodied therein the necessary make-ready as may be required to compensate for errors well known to pressmen, such as errors found in the type body itself, or peculiar to the particular press upon which the printing is to be done.

Furthermore, such make-ready as may be deemed advisable for securing the desired graduation of pressure may, in addition, be incorporated in the plate during the formation of the latter..

In the practice of the invention suitable make-ready may be used, it being understood that, irrespective of the character of the make-ready, the plate as finally completed and ready for use on the press will have the necessary regularities and irregularities therein, produced through the agency of such make-ready as may have been employed. By preparing the plate with the make-ready as hereinafter described, I obviate the necessity of tedious make-ready operation usually necessary on the part of the pressman in equipping the press with plates for printing purposes.

My invention consists in the improved printing plate and in the method of producing the same set forth in and falling within the scope of the appended claims.

In the accompanying drawings:

Figure l-is a view in elevation of a conventional form of press and showing a plate in the course of manufacture in conformity with my invention.

Fig. 2 is a view illustrating the completion of the operation of making the plate shown in Fig. 2. 1

Before entering into a detailed description of the invention I will briefly state that in the practice of the same I resort to the use of pressure for the purpose of producing in the plate the necessary regularities and irregularities to conform to the makeready employed, and for this purpose any suitable press may be employed, preferably one capable of exercising both heat and pressure,-such as a hydraulic press having heated platens. Furthermore the plate itself may be of any suitable material, such as a plastic composition, metal, or the combination of these, and therefore I do not llmit myself in the present instance to the use of any particular material, it only being necessary to employ some substance for the plate which will be capable of being formed under pressure to conform to the makeready employed.

In Figs. 1 and 2 I have shown my method of making the plate with the make-ready. In Fig. 1 a plate matrix 5 is placed on the bed 6 of a casting box A and between confining bearers 7, which restrict the side-flow of the plate material, as is desirable, especially where the plate is to be made of a plastic substance such as a phenolic or phenolic condensation product. A sheet of plate making material 8 is imposed upon the upper or molding faceof the matrix and negative make-ready 9 is properly positioned against or upon the back of the plate material 8. The upper plate 10 of the casting box is now closed and the plate is molded on the matrix made by subjecting it to pressure, or to both heat and pressure, while in the closed casting box. The result will be that the face of the plate making sheet 8 which lies against the matrix will be molded to produce a reverse facsimile of the matrix molding face, and at the same time such negative make-ready 9, as is employed will be molded into the back of the plate. A thin sheet of foil or other suitable material may be employed between the negative make-ready and the back face of the plate during the pressing or molding of the plate against the matrix, in cases where the plate is made of a plastic material such as phenolic substance, as the use of such foil will permit the ready separation of the make-ready from the back of the plate when desired. After the plate has been molded against the matrix as shown in Fig. 1, it may be removed from the casting box and separated from the matrix, and at the same time the make-ready is removed from the back of the plate. This plate may then be placed upon the flat bed of the casting box or press and a resilient blanket or packing 11, as shown in Fig. 2 imposed upon the printing face 8' of the plate. The box or press is now closed and the plate thus again subjected to pressure, or to heat and pressure, if desired, against the fiat bed of the box or press so that the regularities and irregularities produced in the back or 'non printing face of theplate Will be thrust or forced to the front or printing face 8 thereof, this being permitted by the yielding of the resilient pressure blanket 11, and of course the back face of the plate will be made smooth and level by the pressure thereof against the hard rigid bed of the box or press. I

What I claim is The herein described method of making a printing plate which comprises providing a suitable plate matrix, placing plate making material thereagainst, applying suitable makeready in a predetermined position against the back of the plate material, then subjecting the matrix and makeready and the plate making material to pressure to mold the plate againstthe matrix and to produce in the back of such plate regularities and irregularities in conformity With the makeready employed, then removing the makeready and matrix, and then subjecting the plate to pressure against a yielding body and between the platens of a press to force the regularities and irregularities from the back to the printing face of the printing plate.

In testimony whereof I have hereunto set my hand.

EMIL E. NOVOTNY. 

